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Smith & Wesson’s M&P15T Tactical Carbine

Smith & Wesson is one of the oldest and most respected firearms manufacturers in America. When the company decided to enter the AR-15 market, it was clear that the S&W product couldn’t be just another AR clone. The resulting, high-end patrol carbine incorporates the best features for tactical capability and enhanced reliability. The M&P15T has features that set it apart from similar carbines.

Reliability enhancements include hard chrome plating of critical components such as bore, gas key and bolt carrier. Both upper and lower receivers are forged 7075-T6 aluminum, hard coat anodized. We found absolutely no play or “slop” between the upper and lower receivers, indicating that they were carefully mated. Clearly this is a top end carbine designed to withstand any kind of abuse that it might encounter during a life as a patrol carbine for law enforcement use.

The M&P15T has a the Modular Rail Forend (MRF) that free floats the carbine’s barrel. Free floating means that the barrel is attached to the carbine at only one point—the receiver where it is retained by the barrel nut. The forend doesn’t touch the barrel at all. This enhances accuracy by allowing the barrel to resonate freely when the carbine is fired and as the barrel heats up during qualifications or extended engagements, the barrel expands evenly, again enhancing accuracy.

The day of bare carbines is long over. When optics, white lights and lasers are mounted on a conventional two-point handguard like that of the original carbine, zero can be affected, so most special warfare units now mount free float handguards of some type to prevent zero change.

The first addition we made to our test M&P15T was a 4x32 Trijicon TA31 ACOG (Advanced Combat Optical Gunsight) sight, known by the U.S. military as the AN/PVQ-31 Rifle Combat Optic (RCO). The Marine Corps has already announced that it will equip every M16 in its inventory with this sight. The TA31 isn’t cheap, but it has the features that the military wants, including battery-free operation, instinctive aiming with both eyes open, ballistic correction and range capabilities that run from close quarters battle (CQB) to 800 meters using the internal bullet drop compensator.

The RCO’s reticle is illuminated either by fiber optic or tritium, so the RCO is capable of use in bright light, low-light or no light. The RCO is rugged, being machined from a 7075-T6 aircraft aluminum forging, is totally parallax free and is waterproof to 100 feet. Optics are coated to MIL-C-14806A, giving 90% light transmission. Different reticles are available, depending on customer requirements.

Vltor’s Modstock is a perfect complement to the optics and other accessories we installed on the M&P15T. The Modstock system replaces the standard collapsible stock. The Modstock has compartments that provide a flat ergonomic cheek-rest that positions the shooter’s eye exactly where it needs to be for either optics or open sights. The compartments provide waterproof storage for AA and 123 size batteries, or other small gear and can be accessed without removing the stock from the buffer tube.

One note of caution…all collapsible stock buffer tubes are not the same! Military specification buffer tubes have an outside diameter (OD) of 1.150 inch, while the OD of commercial tubes is 1.170 inch. To make matters even more confusing, the threads for attaching the tubes to the lower receiver are the same for both tube diameters.

The M&P15T came with a Mil-Spec diameter tube, so all we needed to do was change out collapsible stocks. We should note that the vast majority of M4-type carbines have commercial buffer tubes. Kudos to Smith & Wesson for using Mil-Spec buffer tubes. If the AR rifle has a full length stock, there are no issues. All fixed stock buffer tubes are the same OD.

Another recently adopted military device is Laser Devices’ DBAL-A² (Dual Beam Aiming Laser-Advanced²). Laser Devices has been awarded a multimillion dollar contract for the DBAL-A², which the military describes as a “Multi-Functioning Aiming Laser System.” The DBAL-A² is in use by both Army and Navy special operations units. Features include an IR pointer, IR Illuminator and red visible laser pointer.

The illuminator is adjustable from spot (narrow beam) to flood (wide beam). A low-power engagement mode reduces the IR output for use indoors and for CQB. Optical glass generators project different illumination patterns, including circle, square, triangle, plus sign or “T” for target designation and pointing. Windage and elevation are adjustable in 0.4 milliradian increments. Operation is from a remote paddle switch mounted on the carbine handguard.

Most tactical units usually mount a white light of some sort. In this case, we used one of Laser Devices’ “Operator” high-intensity white lights. The 6-volt Operator is powered by two 123 batteries, has an out put of 125 lumens and a nominal continuous run time of about 1.75 hours, depending on ambient temperature.

With our M&P15T thus equipped, we were ready to let some local law enforcement colleagues try it before we did our formal range testing. Every one who handled the M&P15T was impressed by its overall high quality and versatility. Everyone especially appreciated the Troy backup iron sights that—unlike many others—are fully adjustable for elevation and windage.

Shooting the M&P15T was just what we have come to expect from recent Smith & Wesson products…total reliability and excellent accuracy. We test fired the M&P15T at 50 yards, as this represents the average police long-gun engagement. The single-stage trigger broke cleanly at 6.5 pounds with a tiny bit of creep and no backlash. Factory spec is 7 pounds, but we have found over the years that most good factory AR triggers break in the 6- to 6.5-pound range.

We can recommend Smith & Wesson’s M&P15T to any person or agency that is seeking a high-quality reliable and accurate M4-type enhanced carbine. The MP15T has what it takes to get the job done.

Charlie Cutshaw is a small arms, ammunition and infantry weapons editor for Jane’s Defense Information. He served as an Army infantry, ammunition and intelligence officer before retiring in 1996. His military assignments included a tour of duty in Vietnam as an adviser. He currently lives in Alabama, where he is a full-time writer and reserve officer. He can be reached at CQCutshaw@aol.com.